This invention relates to improvements in means for mounting electrical devices or other apparatus in the space between an adjacent pair of concrete railroad ties and, in particular, to a mounting means which does not require the drilling of holes in the ties or the use of special fasteners cast in the concrete.
Wooden railroad ties ultimately require replacement after years of use and exposure to the elements. With lessening availability of timber having the size and durability characteristics needed for quality ties, the use of railroad ties cast from concrete has become widespread. Although the concrete tie is a suitable substitute, concrete is not as convenient a material in the field when the ties must be used to support electrical or mechanical devices along the track. A particular problem is presented with respect to the mounting of impedance bonds that are widely used in the operation of electrified trains.
The bond device comprises a large inductor enclosed in an essentially cubical housing approximately nine or ten inches (22.5 to 25 cm.) in height, length and width. When mounted between the rails and connected thereto, the bond provides a direct-current short for the propulsion current but sufficient impedance to accommodate alternating current track circuits. With wooden ties mounting is a simple matter as brackets may be simply nailed to the adjacent ties between which the bond is placed.